spatial lec

Question 1

as rat walks to gt food what is it learning?

Answer 1

distinction between goal-directed behaviour and the stimulus-response type behaviour.

• 1 camp - S-R animal merely learns a response - turn right
• like a habit
• 2nd camp - Tolman (purposive behaviourism) - animal can learn purpose of their behaviour
• so animal turns right because it knows there’s food there

Question 2

how can you study whether the animal is learning via SR or the goal-directed learning

Answer 2

• train them with one, then test with the other
• e.g., always starts from south and turns left to get food
• then test starting from diff point where they should turn right to get food
• if they can then they learned via the response strategy - they will still turn right, if learned where the gfood was it can turn right
• so the animals will do different things depending on the learning strategy used

Question 3

response vs place strategy

which strategy do animals choose?

Answer 3

depends on various factors

• how obvious the spatial cues are
• how obvious the turn is - maybe a 160 degree
• how much training they have
• how stressed they are

Question 4

morris et al., (1982)

water maze study with hippocampal lesioned rats

Answer 4

• trian rats with hippocampal lesiosn to locate platform in water maze
• trained rats to locate platform in one quadrant
• if platform was visible (above water level) rats with leisons could find it
• if it was invisible, they couldn’t find it - search equally each 4 quadrant of the pool
• controls: who underwent a process of surgery but didn’t acc get any damage; cortical lesion - receive damage in diff area - both showed preference for the correct pool quadrant. only hippocampal lesion n searched all 4 quadrants the same

Question 5

hartley et al., 2007

four mountains task

Answer 5

virtual version of piagets 3 mountains task. looks at perspective-taking, recognising the same scene of an environment from different angles

two versions

• version 1: spatial memory test
• version 2: non spatial memory test

results

• non spatial verison = no difference between n with hippocampal damage an controls
• spatial version = hippocampal lesion n = perform much worse than controls

Question 6

Tolman’s response vs place learning - which is H importnat for?

Answer 6

also there we found the hippocampus was important for place learning

Question 7

Packard and McGaugh (1996)

Answer 7

• surgery - cannula placed in either the hippocampus or dorsolateral striatum
• trained them to always run from. thesouth arm and turn right to get food
• end of training they rotate arena - let them start probe trial from opposite side
• then do reversible inactivation - infuse into cannula an anesthetic lidocaine
• so half animals in the H and half n in the DS group they inject the anesthetic and other half they inject sailine
• anesthetic shuts down neurons. inthe local area you putt he lidocaine. in- temporarily stop animal from using either H or DS
• reason they do this reversible activation on the probe trial after 8 days of training then again after 16 days
• want to leave the H and DS intact the entire rest of its time

after 8 days training - PREFERENCE FOR PLACE

• most animals in Saline group follow the place and not the response
• normal animals with normal function brain predominantly show palce learning after 8 days training
• when inactivating DS - no effect on place learning
• when inactivating H - animal has equal preference for place vs response learning. this could be due to them having an equal preference OR them having no preference
• if normal animals do place learning, and at test if shutting down the hippocampus impairs that ability to use this strategy it shows that they learned initially via place learning and cant use it now

after 16 days of training - PREFERENCE NOW FOR RESPONSE STRATEGY

• learning response happens with additional training (like habit)
• when inactivating H - has no effect on that response strategy
• when inactivating DS - has massive effect, animal doesn’t just not know what to do here but completely flip to place learning
• not that the animal doesnt know where to go - it has a memory for the place and youve reinstated its memory for place by shutting down the response learning strategy

interpretations

• short term training -place learning,
• long term learning - response learning
• place learning handles by H
• response learning handled by DS

Question 8

hippocampus is involved in which type of learning strategy

Answer 8

place learning (learning to go to a specific place, knowing food is located there)

Question 9

dorsal striatum is involved in which type of learning

Answer 9

Response learning (remembering the specific responses only, e.g., I went left then right then left)

Question 10

place and response learning are argued to rely on different kinds of associations.

how do we know that place learning is actually reflecting goal-directed behaviour?

Answer 10

Kosaki et al., (2018)

• trained rats to go somewhere for chocolate pellet
• after this - initiated postconditioning outcome devaluation - did this using flavor specific satiety
• one day give them loads of chocolate pellets (in their home cages)
• another day give them loads of their maintenance diet (again in their home cage not the study
• NOW did the study and if the animal goes to the food side of the T shape - shows they did response learning
• if they however go to the food-free side it shows they did place learning becasue they KNOW the food is there but are so full of the food they dont wanna go

results

• animals that werent stuffed with the food showed equal preference of both response and place learning
• when stuffed with. thefood - they stopped visiting the arm associated witht he food annd went to the opposite arm
• means they deliberately going to the ofod location shows they did goal-directed learning and associated that arm witht he chocoolate pellets

Question 11

so devaluing the outcome had an effect on place learning, but how can we make sure it DIDNT have an effect on response learning

maybe it had an effect on both strategies and place learning is the one they were predominantly interested in doing. devaluing just knocked down place learning and inadvertently pushed up response learning.

Answer 11

force the animals into doing response strategy learning (done by lesioning the hippocampus)

then repeat Kosaki et al., (2018) study

experiment 2

• previous experiment - no preference of either strategy in the non-devalued condition
• with devaluation, animals with no lesion - they still go to the food pellet bit (response straegy) but once they get to the choicepoint they are slower going there almost like ugh food there, full of food, but I dont know where else to go
• while rats with hippocmapal lesion show the initial rapid response learning - go straight to the food even though they are full of chocolate pellets

Question 12

what do we learn from Kosaki et al (2018) study

Answer 12

outcome devaluation has no effect for the response strategy but does effect the place learning strategy

Question 13

how does outcome devaluation affect habit learning/lever pressing in rats

Answer 13

lever pressing in rats

• if you train them a small amount in leaver pressing then do outcome devaluation then they don’t wanna press the lever anymore
• if you train them a lot then they continue pressing the lever despite outcome develuation

fits nicely twith Packard finding of rats after short time learn place elarning strategy but then after long time (16 days) they learn response learning strategy. so overall ealy on n are represetning the outcome hen with continued training stop focussing so much on the outcome as the response strategy is too strong.

So we see a sort of flip from them caring about the outcome to not caring about the outcome

Question 14

how do we know place learning is handled byt he hippocampus

Answer 14

• morris water study
• four mountains H lesion task
• t maze - place learning impaired with inactivation of the hippocmapus

Question 15

Why dont we have so much studies on dorsal striatum damage from humans compared to

Answer 15

difficult to see in humans

• difficult to see damage in the basal ganglia
• easy to see damage to the hippocmapus as its close to the blood brain barrier - particularly sensitive to trauma
• BG doesnt seem to be the same

Question 16

place learning - what association are they actually learning

Answer 16

learning about the relationship between cues in the environment and the location they need to get

Learn how to move towards goal

Question 17

response learning - what association are. theyactually learning about

Answer 17

only cares about turning left. can just close your eyes and do it

its all based on the muscle memory

Question 18

Dorsal striatum is involved in other thngs not just remembering to turn left

Answer 18

• packard showed DS was important for stimulus-response learning strategy in a T maze
• devon and white - showed it was important

Question 19

Devan and White study (1999)

Answer 19

• did irreversible lesions: DLS, DMS, Fornix lesion
• trained rats to find paltform indicated by the cue
• animal trained to find platform with beacon attached
• test trials - moved the beacon to the opposite side of the pool.
• so can dissociate the place where the platform has been throughout training form the cue - indicated where the platform was
• released the rats into the pool and divided them up into groups of “cue responders” and “place responders”

results

• sham animals equally visited the cue furst just as much as they visited the place first
• hippocmapal lesioned n were all cue responders (place learning has been disrupted by the lesion to the hip)
• DS lesioned animals - visited the place first then eventually go to the cue second

interesting, so they do go to where the cue is but they all go tot the place first. as if lesioning the DLS has decreased the salience of the cue.. dont learn so much about hte cue as they learned by the place.

learning about the cue is impaired by the DLS lesion

Question 20

what can we infer from devon and white study

Answer 20

cue learning/beacon learning and response learning - share the same part of the brain (DLS)

Question 21

pearce, robers and Good (1998)

How did they show the DLS is involved in spatial strategies

Answer 21

• attached landmark (ballcock) to a rod
• per each session animal undertook 4 trials
• for each trial they learned the location of a platform and it was in a fixe dlocation form the landmark (E.g., every trial is is south of the landmark. the landmark had the fixed relationship with. theplatform for 4 trials a day
• but then the next day the ballcock is moved ot a new location
• so each day the platform has a fixed relationship to distal cues outside the pool and a fixed relationship to the local cues (ballcock)
• sham animals from trial 1-2 got better at learning the location of the platform with each trial
• hippocampal lesioned rats diddnt get quicker from trial 1-2
• interestingli H lesioned rats were quicker finding the platform on the 1st trial - had an advantage

why

werent set back by the memory of where the platform was the day before. sham animals must have located in in accordance with distal cues (are these weighted heavier than local cues? check that study)

these animals were just using the landmark-platform association

Question 22

how did pearce et al test that the hippocampal lesioned animals were faster locating the platform in trial 1 BECAUSE they were using only the internal landmark to guide movment

Answer 22

• moved the landmark to a new location that they never tested them at before
• 1 trial put the platform on the right side of the landmark (20cm south) then another trial put the platform 20cm north

results

• found both hippocampal lesion and shams were quick to find the platform when it was on the right side and slower when it was on incorrect side
• hippocampal lesion didnt show any imparment in this the implication of thisis that rats with hippocampal lesion can learn limitted spatial memory based on a simple landmark-goal vector as opposed to learning a map of the environment based on cues around the pool

paper dissociated landmark learning from cognitive mapping

Question 23

How did pearce study dissociate landmark learning from cognitive mapping

Answer 23

because they found the hippocmapal lesioned n were fine learning about a platform location using landmark cues however struggled learning the location using a wider cogntiive map of the environment

Question 24

Kosaki et al., (2015)

Answer 24

design

• 4 trials one day with the same platform-landmark association and external cues
• next day different location
• lesioned both hippocmapus and DLS

results

• took the platform awar and measured how long rat searched the correct vs incorrect side of where the platform was relative to landmark
• sham and hippocampal lesion n spent mor time searching the correct side - shows the internal landmark goal vector is not impaired by a hippocmpaal
• DLS lesion n - cant learn the association between landmark and platform

Question 25

DLS important for learning landmark-goal associations

human study?

Answer 25

Doeller, king and Burgess (2015)

• basically converted the pearce paper into a humna virtual navigation task (not lit vr, just online game)
• trained n to learn the location of different objects by referencing them in relation to a landmark
• mountains provided as distal cue
• boundary also there to help locate it

manipulation part

• In one experiment 2 objects that always fixed realtinoship to a boundary and 2 other objects with fixed location to a landmark
• asked n to re-locate the object

results

• when learning and remembering the objects position with respect. tothe ladmark - the DLS was active
• when they learned the location of hte object with respect tot he boundary - the hippocampus was active

Question 26

Doeller and Burgess (2008)

how did they show information learned from. aboundary overshadows information learned from the landamrk

Answer 26

n learn the location of object with respect to EITHER:

• a landmark and boundary
• landmark only
• boundary only

looked at accuracy - how accurae people are when using either of these 3 things as references

results

• n trained with both - if testsed with just the landmark n werent accurate. compared this with control who had been trained with landmark alone throughout.
• meant the boundary restricts/overshadows learning about the landmark
• however if n trained using both - and you just remove the landmark. n really accurate!
• the presence of the landmark had no effect on accuracy, know this bc they compared this to group trained with boundary only

Question 27

what is overshadowing?

Answer 27

when someone trained to learn something e.g, the location of food using two things e.g., a tone or a light

test how much they learned about the tone. compare this to group who only ever learned about the tone. cue competition influences how much information you have learned from one cue vs another

Question 28

Doeller and burgess (2008) study showed theres no cue competition when learning about spatial locations using boundary vs landmark

why is this important?

Answer 28

it indicates the H act independently of other parts of the brain. when forming the memory of a location you do this without influence from other types of memory.

doesnt obey the normal rules of associative learning in that you dont get overshadowing

the lack of overshadowing is evidence against the rules of associative learning

this is important as it supports cognitive modularity (forming a cogntiive map)

Question 29

what is cognitive modularity and how do doeller and burgess study support the notion of it?

Answer 29

cognitive modularity of cognitive map

if you have a cognitive map built in your hippocampus, you want to include in this map new things you encounter in the world. this theory of cogntivie mapping comes from o’Keefe’s work on place cells and burgess’s work on place cells

transplanted this idea to human spatial learning as well

however there are alternative explanations for this.

Question 30

Kosaki et al., 2015

enhancing effect

Answer 30

• trained them few trials to platform in fixed location with respect to the landmark
• then removed the platform and landmark and investigated where the rats spent searchign for the platform -
• do they look for where it was the last 3 trials
• or do they look radomly (spend equal time in all 4 quadrants)

Expect sham animals do be sound locating hidden platform using the room cues IF learning using the:

• landmark (DLS)
• and cognitive map (hippocampus) exist independently of each other! (they don’t need the landmark!)

results

• hippocmapal lesion n dont know where to go search randomly - not surprsing as they depended on the now removed landmark
• shockingly - sham animals dont know where to go
• even more surprisingly DSL lesion group show a facilitation effect!!

presumably bc DLS lesion n have no memory of the landmark so the location of the landmark is not interfering with their mental processes or overshadowign their memory for place based on the external cues

while sham animals did suffer this. havent learned as much about the external cues as DLS n as learning the location of the platform using the presence of the landmark has overshadowed the learning based on the eexternal cues

Question 31

facilitating place memory by lesioning the DLS (Kosaki et al., 2015)

any evidence for opposit effect? facilitating landmark memory by lesioning the hippocampus?

Answer 31

poulter et al., (2019)

• trained rats in water maze with 2 landmarks: a tennis ball and stripey thing
• rats with hippocmapal lesions were trained to find the platform under one of those 2 landmarks
• could learn the location of landmark with reference to landmarks
• or could learn to find the landmark with reference to the external cues
• both strategies available to them

then probe trials

• curtains drawn around the pool hiding the external cues
• landmarks are rotated to occupy novel positions now
• and platform taken away
• measured how much time n spent searching under the correct landmark vs the incorrect landmark
• basically asking: during training how much did you learn about the elandmark when the external map was available?

results

• hippocampal lesioned n show enhancment in learning about the landmark
• prob bc hteyre unencumbared by the memory of a cognitive map - havent acc got this map
• sham animals show a weaker effeect, dont know as much about the landmark as the hippocampal lesion n do. presumebly because they do have the memory of the map.

Question 32

poulter et al., (2019)

how do we know the H rats were actually impaired on the spatial task?

Answer 32

trained them on a ractangle. classic measure fo spatial memory - n cant learn position of platform in a rectangle

sham animals could

Question 33

discuss evolution of DLS role in the literature

Answer 33

early evidence suggest DLS it wasnt involved in spatial learning, just involved in directions/responses/following beacons

but since studies have shown the DLS cares about a spatial relationship between 1 onbect and another (shown in animals, doeller king and burgess showed it in humans)

Question 34

what did doeller and burgess argue ?

and why is this important?

Answer 34

learning using the hippocampus takes place regardless of other cues e.g., the presence of a landmark

tells you about tcognitive modularity - this part of the braina cts independentl yof other parts

Question 35

whats are 2 limitations of the doeller and burgess (2008) study

Answer 35

if n trained using both landmark and cues then at test you just give them one then they might just be confused by the change of things and this influences performance. Thinking eh? wheres this boundary?

impoartant then. tohave a good control, maybe the control group of boundary/landmark only isnt such a good control because they didnt lose anything from training to test

secondly

• n trained with boundary and landmark then take landmark away and say oh look they learned using the boundary
• but they dont always see the landmark and object so if you wanna know the relatinship between the landamrk and object
• you could only see it when approaching the scene from a certain direction
• maybe thats whats going on here - sometimes n cant see the landmark when theyre beign trained here they cant see it so much